Parent.prototype.getName = function() {
  return this.name;
}
function Parent(name) {
  this.name = name
}

// Child.prototype = new Parent()  // 原型链继承
Child.prototype = Object.create(Parent.prototype)
Child.prototype.constuctor = Child

function Child(name) {
  Parent.call(this, name)  //  构造函数继承
  this.age = 18
}


let c1 = new Child('Tom')